Large capacity facilities or arenas are generally used for a variety of entertainment and athletic purposes. When one of these purposes is basketball, a portable hardwood floor must be placed on top of the base floor, which may be concrete, plywood, a synthetic surface or even ice.
Most portable hardwood floors comprise a plurality of interconnected 4'.times.4' or 4'.times.8' rectangularly shaped sections. Typically, each section includes an upper wear surface of elongated, hardwood maple floorboards or a plurality of maple parquet elements arranged in a rectangular configuration. One or more subfloor layers may be used to support the wear surface, with the one or more layers being elongated sleepers which may be either narrow or relatively broad. One or more subfloor layers of panels may be used to simulate one of the desired qualities of a permanent hardwood floor system, i.e., dimensional stability. In either case, the lowermost subfloor layer is supported directly on the base.
One common problem associated with portable floor systems of this type relates to interconnection and disconnection of the rectangular sections before and after an event for which the floor is needed, such as before and after a basketball game. Each section must be connected in flush, perimeter engagement with the other, adjacently situated sections. This requires initial placement and connection of a first row of floor sections, followed by row by row placement, maneuvering and interconnection of the other sections with the already connected sections. During this process, frictional forces between the bottom surfaces of the sections and the arena floor make placement and maneuvering difficult, time consuming and labor intensive. Typically, installers must hit the sides of the floor sections with a large rubber mallet to move them into proper position. Over a period of time, impact from the mallet will cause wear and tear along the edges of the floor sections.
Additionally, the direct contact of a bottommost subfloor layer with the base may cause damage to the base, particularly if the base is wood or synthetic. At the very least, a base of this type must be covered for protection. If the base is ice, direct contact therewith causes some melting and water transfer to the floor sections, thereby making them heavier and accelerating deterioration.
If the sections of the portable floor system are supported on rubber pads to provide resilience for the floor system, friction between the floor sections and the base is further increased, and this increased friction inhibits the lateral maneuverability of the sections. Thus, while some resiliency for the final floor is achieved, installation becomes inconvenient, resulting in higher costs. This increased friction may loosen or knock some of the pads off of the bottoms of the floor sections. Also, the increased friction will necessitate increased use of the mallet to move the floor sections into position, thereby accelerating the wear and tear caused by mallet use. The frequent handling of the portable sections also knocks pads from the bottoms of the sections. With some pads missing, the resiliency will not be uniform. Thus, the increased friction caused by bottom-mounted pads results in inconvenience during installation and a decrease in the uniformity of resiliency for the portable floor.
Koller U.S. Pat. No. 4,860,516 discloses a portable floor system which includes compressible pads located between upper and lower spaced subfloor layers. The spaced subfloor layers protect the pads and prevent them from being rubbed off the bottoms of the sections during lateral movement on the base floor.
However, due to the increased surface contact between the lower surfaces of the bottommost layer of the sections and the base floor, and the increased friction which results therefrom, these sections are difficult to move laterally along the base into alignment with already connected floor sections. Thus, while the pads are protected, this advantage is accompanied by a corresponding increase in the difficulties associated with maneuvering the floor sections into alignment during connection. Moreover, this particular floor has a relatively high vertical dimension, which represents a safety hazard around the edge unless an inclined perimeter is mounted thereto. Such a perimeter represents an added cost in material, labor and storage.
It is an objective of this invention to facilitate the interconnection of a plurality of interconnectable sections of a resilient portable hardwood floor system.
It is another objective of this invention to improve the dimensional stability, the resiliency and the uniformity in resiliency of a portable hardwood floor system, and at the same time to reduce the difficulties presently associated with maneuvering, aligning and interconnecting the floor sections of such a system, and to reduce safety problems and/or higher costs caused by a high vertical dimension.
It is still another objective of the invention to improve the resiliency of a portable hardwood floor system in a manner such that the resilient support means is neither susceptible to excessive wear and tear during frequent handling nor disadvantageous during installation.
The objectives of this invention are achieved by a portable floor system comprising a plurality of interconnectable sections, each of the floor sections supported by a plurality of mounts which include non-compressible, low friction glide members in direct contact with the base.
The non-compressible, low friction glide members enable the floor sections to be relatively easy to maneuver and slide into alignment for interconnection. Thus, because this invention reduces friction between the floor sections and the base, it represents an improvement over portable floors which include a subfloor in direct contact with the base.
Due to the reduced co-efficient of friction of the glide members with respect to the base, and because of their rigidity, the mounts are also substantially less likely to be knocked off the bottom of the sections during lateral movement, compared to unprotected rubber pads. Moreover, the reduced friction reduces the need to hit the sides of the floor sections with a rubber mallet to move them into proper position.
Preferably, the mounts are vertically compressible, and the compressibility of the mounts provides resiliency for the interconnected sections of the portable floor system, regardless of whether the base is concrete, wood, synthetic or even ice. The use of a plurality of mounts to support the floor sections above the base further reduces friction by reducing the surface area of contact with the base. Additionally, if the base is ice, the mounts eliminate water transfer to the floor sections.
According to a first preferred embodiment of the invention, each portable floor section has a wear surface of floorboards, at least one subfloor layer and a plurality of mounts which comprise compressible and deflectable pads secured to the lower surface of the bottommost subfloor. The pads have a truncated conical shape, with a base portion of the conical shape secured to the lower surface of the bottommost subfloor layer and an apex portion extending downwardly therefrom. There is no vertically continuous line of material between the base portion and the apex portion. Also, under no load conditions, the surface area of contact of the base portion with the subfloor is removed laterally from the surface area of contact of the apex portion with the concrete.
A nylon glide member or tip is embedded in the apex portion of each of the pads. The glide member is slidable with respect to the concrete base which is typically used in multi-purpose arenas. Thus, the glide member reduces the co-efficient of friction of the portable floor section with respect to the base.
According to a second preferred embodiment of the invention, each of the interconnected sections of a portable floor system is supported by a plurality of compressible mounts which comprise a compressible and deflectable pad encased within an opposed pair of vertically aligned and interconnected cups. Each pair of cups forms a encasement which encases a respective pad. The upper cups are attached to the lower surface of the bottommost subfloor layer and open downwardly. The lower cups open upwardly and receivably interlock with the upper cups, with a pad held therein. Preferably, the pad has a truncated conical shape.
Once connected, the cups may move toward each other along the axis of connection, upon impact to floorboards above. The amount of movement is determined by the compressible and deflectable characteristics of the pad. Also, the sizing of the cups provides an automatic stop mechanism for limiting vertical deflectability to a predetermined distance, which is preferably about 5/16". When the pad is located inside the two interconnected caps, with no compressive force applied to the cups, the pad is not compressed. Stated another way, the cups move away from each other to a distance which is equal to or slightly greater than the vertical dimension of the pad.
Upon impact to the floorboards thereabove, the pads compress vertically to allow relative vertical movement between the interconnected cups, thereby providing resiliency for the portable floor system. Because of the vertical dimension of the pad with respect to the inside of the cups, deflection is high at impact, but deflection is confined to a relatively small surface area of the floorboards. Perhaps most importantly, the low friction composition of the cups, which are preferably nylon, allows the floor sections to slide relatively easily over the concrete base to facilitate maneuvering and alignment during interconnecting of a plurality of portable floor sections.
In a variation of this embodiment, the upper cups may be partially embedded or countersunk within the lowermost subfloor layer. This reduces the overall height of the floor sections, thereby reducing the volume of space required for storing and reducing safety concerns and/or the cost of an inclined perimeter, both of which are associated with high profile floors.
For each embodiment, compared to portable floor sections equipped with either a planar bottom layer in direct contact with the base, or a plurality of rubber pads in contact with the base, the rigid, low friction glide members reduce the co-efficient of friction between the floor sections with respect to the base. If the glide members are nylon, the floor sections maintain their slidability, due to the somewhat self-lubricating nature of nylon.
With a plurality of compressible mounts supported and carried by the lower surface of the bottommost subfloor, the subfloor of each section of the floor system is raised above the base. Thus, it is easy for individuals to grasp, lift, maneuver and carry the sections during connection and disconnection.
Additionally, for a floor system wherein the floor sections have sleepers on the bottom and in which the mounts are partially countersunk in the floor sections, spacing blocks may be secured between the sleepers, in perpendicular orientation thereto, to assist stacking of sections in a manner which does not apply any compressive load to the mounts.
For each embodiment, to further confine the total surface area of deflection under impact from above, as explained in all of applicant's preceding related applications, kerfs may be provided in one or more of the subfloor surfaces and/or the bottom surface of the floorboards.